Process for the production of cellulose by decomposition of vegetable fibers



Patented Feb. 7, 1928.

UNITED STATES PATENT; OFFICE.

OTTO C. S'JJREGKER, F DAB IMSTADT, GERMANY.

raoonss FOR THE PRODUCTION or onLLuLosn BY nnoom'osrrron or VEGETABLE means.

Ho Drawing. Application filed September 21, 1W5, Serial iq'o. 57,755, and in Germany September 30, 1624.

In order to obtain cellulose from vegetable fibers as is well-known, it is usual to decompose them by means of alkaline 'or acid liquids for the active constituents of which a large series of diflerent materials have been used or proposed for use.

According to the 4 present invention I use for this purpose decomposing liquids which contain one or more soluble oxy-compounds of the isocyclic series in which one.

hydrogen atom has been replaced by a metal.

A plurality of these hydrogen atoms may i be replaced by metal; and a plurality of these hydrogen atoms "may be replaced by, metal and by. a non-metal. As such non- V metals, chlorine, bromine, iodine, nitrogen dioxide or nitro-groups are suitable.

As metals, preferably the alkali and alkaline earth metals as well as the metals of the magnesium group can be used. The following materials can be used for example as oxy-compounds of the isocyclic series,the international so-called Geneva terms being added in brackets:

(1) Phenols, for example phenol (oxybenzol G H O) or cresol (oxytoluol G,H O)

(2) -Alcohol phenols for. example phenolalcohol (oxybenzylalcohol or dioxymethylbenzol 0 11 0 3O (3), Phenol-acids for example metaoxybenzoic acid ((3 1-1 0 .(4) Cyclohexahol (tetrahydrophenol 0 H 0) (5 Hydrated phenols, for example cy-- and functional derivatives.

can be used for which barium hydrate and 5 clohexa'nol (hexahydrophenol C l-I 0); j

(6) Naphhols; for example naphthol (oxgnaphthalin C H O) Hydrated naphthols, for example oxynaphthalintetrahydride O H O or ox y' na hthalindecahydride O H, O;

8) Methylcyclohexanol toluol 6711, 0)

(9) Polyoxides for example resorcin (dioxydbenzol G H (10) Oxysulphones G, H,..O -SO (11) Monoand polycarbo-acids or sulfo-' acids C H,-SO -O or their basic and neutral salts.

Further the homologues of the, above indicated materials can be used. The position of the atoms in the constitution of these materials is immaterial. For example, the ortho-, metaand 'para-cresols can be use equally well, singly or mixed.

The metals combine with the oxy-com- CQSS.

(hexahydrooxys pounds to form salt-like alkaline reacting compounds which are known, for example, as phenolates and phenolalcoholates.

It is permissible to use the bases in ex- For the decomposition the compounds are used in the form oztv solutions or permanent, i. e. not separating, emulsions. If the compounds used are soluble in water or other solvents such as in soap, or in hydrocyclanols andtheir homologues, the preparation of solutions gives no difiiculties. The production of permanent emulsions also is simple, if to the solution of the one constituent can be added the other constituent without causing flocculent precipitation. If the production of solutions or permanent emulsions gives rise to difliculties this canbe overcome by the addition of certain auxiliary materials, for example castor oil soap orcyclohexanol, which hold the mater al in question in solution or emulsion. Under the different additions which can be used accordmgto requirements those can be" selected'which increase, diminishor do not afiect at all the decomposing action of the liquid on the vegetable fibers.

For the more rapid vegetable fibers further additions can be used. The followingexamples may be mentioned; alkaline, ;'neutral or acid salts, weak acids with neutral or acid reaction, metallic bases, aliphatic or aromatic alcohols, phenol alcohols, together with their homologues Also catalysts barium superoxide may be mentioned as examples. Y

The concentration of the decomposing liq uids made up according to the previous data may be small, in general about 2 to 20 parts by weight per cent suflice. The temperatures which should be maintained during the decomposition need not be high, and it is possi ble to work without increase of temperature. Accordingly no excess pressure at all or only a' slight excess pressure 15 necessary so that penetration of the' the decomposition canj'take place in open vessels or thin-walled kettles.- The time of treatment depends upon thevegetable fibers to be decomposed, the strength of the decomposing liquid, the movement, if any, in the d vessels of the material to be decomposed, the

ted

temperature employed, and the indlca.

Several examples will now for making up the decomposing liquids, ac-

cording to the invention, all of which exam ples refer to 100 litres-of water.

The quantities of the individual constituents vary according to thematerial at the time on hand,

and are not in any case to be consideredas unalterably prescribed. Y I

Ewamgg le Z.-For straw, a solution of alto gether about 2 kgs. cresol', recinoleic acid and methylcyelohexanol in which 1 kg. sod-ium hydrate ispartly chemically combined and partly dissolved. Heating is not necessary but rolling round of the mass should be carried out." r Ewample Q.For wood (for example poplar and pine), about 4.5 kgs. of commercial potassiumhydrate and 8 kgs. cresol and as addition 10 kgs. castor .oil soap. Heating to 120in enclosed vessels.

E wample 3.For straw or wood, about 5 'kgs. of a basic salt of cresol-monosulpho acid, adding. 5kgs. castor oil soap-and 5' kgs. cyclohexariol. closed vessels. b

Example 4.For esparto grass, about 3.5 kgs. potassium hydrate, and 7 kgs. cresol;

Heating to 125 in-enin some cases with'an additionof castor oil soap. Heating to 95 in an open vessel.

- On account of the weakconcentration, the

, low temperature and the slight pressure, the yields of cellulose obtained with the use of" b V the decomposing liquids according to the "invention are considerably more favourable away.

than those obtained with decomposing liquids hitherto proposed'or used. ."The for-J mer apparently do not destroy the cellulose: itself at all whilst. the latter always moreor less attack it, which can be observed without difficulty under Il'llCI'OSCOPlC examination. F or-example, using the new decomposing liquids the inter-cellular proliferations of the cellular vessels are not eaten Since for the decomposing process by means of the new liquids quite slmple apparatus suflice, the possibility arises of carrying it out in districts-which'are not industrial and without skilled work-people. The chemicals used can be manufactured partly from living or dead vegetable products and partly frequently can be obtained from fresh. specimens. The low concentration of the liquids also considerably reduces themanu facturing costs because it avoids process losses. Y J

"Finally the decomposing liquids according to the present invention have the specially valuable property that they do not "attack the metals of the apparatus. It is therefore possible completelypto dispense with the otherwise necessary special linings of the reaction vessels with their well-known disadvantages; lhat .these vessels may beopenv low pressure has been already indicated.

or need only be subjected to The chemicals used can be recovered without any d-ilficulties Worthy of mention.

In order to accelerate the action, higher temperatures thanthose indicated above can also be employed. However, in thatcase, the danger may arise that the decomposing liquids resinify and thus lose the r activity. That can be avoided by adding to the-decomposing liquid a reducing agent of neutral or alkaline reaction. As ,such a reducing agent, I may employ any inorganic or organic compound which is suitable for pre venting an oxidation of the oxy-compounds contained inzthe decomposing liquid. Asexamples may be mentioned: neutral salts of 30 I sulphurous acid, alcohols, glycerine, and their substitution products with alkali. sodium phenyl sulphite' (O H -Q-SO Na) their homologues. and substitution products, M tin and stannous oxide. .The sulphurous acid, for example, does not take part as a whole in the reaction of the boiling process. The derivatives of sulphur can be almost completely separated as metallic salts. I The format on of a sulpho-acid salt, as-in the sul- 99 'phite process, apparently does not takeplace.

' The process of decomposition by means of new liquids is essentially the usual one.

The plantfibers broken up to asufiicient ex tent are treated with the particular liquid at such temperature. and. under such p-ressure as may be necessary. .At the same time a continuous and thorough mixing up of the liquid and the vegetable fibers is advan tageous which can be done by stirring, ro-

tatingor agitating the vessel, circulating the liquid, etc. When the decomposition of the vegetable fibers is completed, the wastev liquid is well decanted from the cellulose, it is rinsed with hot water, boiled and reduced to fibersin the well-known wa'y.

' The cellulose reduced to fibers is advantageously boiled out withalkali, weak soda solution is the best, for'about two hours with vigorous boiling. In this way albuminates .110

' whose hydrogenatoms hasbeen replaced by .metal.

2.. The process for the production of cellulose by decomposition of vegetable fibers,

.which consists in treating said fibers with a decomposingxsolution containing a soluble org-compound of ,the isocyclic series, a. plurq. 'ty; of whotszlvhydrogen atoms has been reaoad by me 3. The process for theproduction of eellulose by decomposition of vegetable fibers,

decomposing solution-containing a soluble oxy-compound of theisocyclic series, one of.

whose hydrogen atoms has been replaced by a metal ofthe alkali group. x

5. The-process'for the production of cellu lose by decomposition of vegetable fibers, which consists in treating-said fibers with a decomposingsolution containing a phenol,

' one of whose hydrogen atoms has been re-- placed'by a metal. a I

.6. The procem for the production of eellulose by decomposition of vegetable fibers, which'con'sists-intreating said fibers with a decomposing solution containing a phenol, a

plurality of :whose hydrogen atoms has been replaced by a metal.

7. The process for theproduction of cellulose bydecomposition of vegetable. fibers,

one of whose hydrogen atoms has been re-- 0 soluble oxy-compound of the'isocychc'series,

which consists in treatingsaid fibers'with a decomposing solution containing a phenol, a plurality of whose hydrogen atoms has been replaced by metal and by a non metal.

'8. The process for the production of cellulose bydecomposition of ve etable fibers,

which consists in'treating sai fibers With'a-IJ produced by the decomposition of vegetable decomposing solution containing a. phenol,

placed by a metalof the alkali group; 9. The process for the production of cellulose vby decomposition of vegetable fibers, which consists in treating said fibers with a decomposing solution containingg, soluble oxy-compound of the isocyclic series, one of whose hydrogen atoms has been replaced by which consists in treating said fibers with'a decomposing solution containing a soluble oxy-compound'of the isocyclic'series, one of whose hydrogen atoms has been replaced. by

a metal, withthe addition to' said solution of castor oil soap. r

1,1. The-process for the luloseby decomposition o vegetable fibers,

which consists in treating said fibers with a decomposing solution containing a soluble oxy compound of the isocyclic series, one of whose hydrogen atoms has been replaced by va metal,- said solutionfurther containing a catalyst.

' 12. The process for the lulose by decomposition o vegetable fibers,

whichronsistsin treating said fibers: with a decomposing solution containing a soluble oxy-compound of the isocyclic series, one of whose hydrogen atomshas been replaced by a metal, said' solution further containing a catalytic barium compound,

13. The rocess for the lulose by ecomposition o vegetable fibers, which consists in treating said fibers with a decomposing solution containing a soluble oxy-compound of the isocyclic series,-one of whose hydrogen atoms has been replaced by a metal, said solution further containing a reducing agent not'havi'ng an acid reaction. 14. As a: composition of matter, cellulose the production of eel lulose by ecomposition of vegetable 'fibers,-

production of cel 1 production of celproduction of cel- I fibers bymeans ofa solution containing a i oT'ro sTREoKER. 

